Definition
The cornea is the transparent front surface of the eye. In keratoconus, the normally round cornea becomes thinned, distorted, and irregular (coneshaped). This abnormal shape prevents the light entering the eye from being focused correctly on the retina and causes distortion of vision. Because of the cornea’s irregular shape, patients with keratoconus are usually very nearsighted and have irregular astigmatism. Occasionally, the cornea may suddenly develop tears on the inner layer. This causes fluid from inside the eye to gush into the tissue causing clouding of vision. This is called acute hydrops.

Causes
The cause of keratoconus is still unknown, but the following patterns are often observed in patients:

  1. Genes. It is not atypical to find several patients with keratoconus within the same extended family
  2. Allergic disorder. People suffering from hay fever, eczema, asthma, and food allergies show a higher percentage of keratoconus than the general population. While this does not indicate causation, it does show correlation.
  3. Down syndrome. This can also be shown to be correlated with keratoconus.
  4. Eye rubbing. Vigorous rubbing has been a common clinical observation among patients with keratoconus.
  5. Hormones. Patients tend to develop keratoconus in the teenage years. Women are also noted to begin showing signs of keratoconus during or after pregnancy. Both of these periods are marked by increased hormonal production.

Symptoms
In its earliest stages, keratoconus causes slight blurring and distortion of vision and increased sensitivity to light. These symptoms usually appear in the late teens or early twenties. Keratoconus may progress for 10 to 20 years and then slow in its progression. It has been associated with severe eye rubbing from allergic eye diseases. Other symptoms include:

  • Nearsightedness
  • Astigmatism
  • Blurred vision, even when wearing contact lenses or glasses
  • Glare at night
  • Eye rubbing
  • Light sensitivity
  • Frequent prescription-changing of glasses and contact lenses

Treatment
Initially, spectacles may improve one’s vision. However, they become less useful as the condition worsens, thus one has to shift to contact lenses. In severe keratoconus, neither glasses nor contact lenses are of any help. Therefore, one may have to undergo one of the two procedures below:

  1. Corneal transplant. This is often performed under general anaesthesia. The damaged cornea is removed and a donor cornea is stitched back in its place.
  2. Cross linking. This is a relatively new treatment, which stops the progression of the disease. It does not reverse the damage already present, though.

To Note
Routine checks by an ophthalmologist are very important because they ensure early diagnosis of keratoconus.

If diagnosed early (when there is still good vision), there is now a surgical treatment called “crosslinking”, which stops or significantly slows down the progression of the disease.

A prolonged period of care after surgery is required to ensure the graft remains healthy.

There is no corneal donation service available locally, so all of UHEAL’s cornea tissues are imported from cornea banks in the USA.

Benefit of Treatment

  • Improved vision

Frequently Asked Questions about Keratoconus
I have keratoconus; will I go blind? No. Keratoconus is not a blinding condition, although vision is likely to progressively worsen. However, with the use of contact lenses, most keratoconus patients can maintain good functional vision and a normal lifestyle.

Is it possible for keratoconus to simply get better and heal on its own, or is it a permanent condition that can only degenerate? Keratoconus either progresses or remains stable; it does not get better.

Will certain activities, such as sports or long hours in front of the computer, hasten the progression of keratoconus? There is no evidence that any physical or visual activity has any effect on the progression of keratoconus. The exception is eye rubbing, where the trauma caused by rubbing the eye can damage the cornea, which may cause the condition to advance more rapidly.

Can I have LASIK? No. In patients with keratoconus the center of the cornea is usually very thin. Therefore, the risk of perforation during LASIK is very high and thus LASIK surgeons will advice against it. You can however have LASIK after a corneal graft is done.